Shock-absorber.



G. C. MARTIN.

SHOCK ABSORBER.

APPLICATION man 1A'N.24, 1912.

1,137,997 Patented May 4, 1915 Maf/www. Ime/@ZEW f Gear* @5w MM Zw;

GEORGE CUSHING MARTIN, 0F OS ANGELES, CALIFORNIA.

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To all whom it may concern.'

Be it known that I, GEORGE CUSHING MAR- 'r1N, a citizen of the UnitedStates, residing at Los Angeles, in the county of Los Angeles and Stateof California, have invented new and useful Improvements in Shock-Absorbers, of which the following is a specification.

This invention relates to that class of shock absorbers shown in LettersPatent of the United States, No. 993536, patented to me May 30, 1911 andalso to shock absorbers of the character illustrated in Letters Patentof the Unitedv States No. 1,039,305 granted to me September Q1, 1912,and which is provided with two relatively rotatable elements, one ofwhich is a circular wall; a shoe to engage said circular wall, said shoebeing normally unconformed to the Wall; Heating means between said shoeand the second element to force the shoes against the wall upon relativerotation in one direction and to release the shoe upon relative rotationin the other direction; and resilient means to hold said floating meansin operative position.

An object of this invention is to increase the period of practical useand to distribute the wear equally throughout the frictional wearingsurface so that the operative life of the shock absorber will beindefinitely prolonged.

Another object is to malte provision whereby too sudden clutching actionis avoided and whereby perfect ease of action in absorbing shocks isinsured.

Another object is to simplify and cheapen the construction of the shockabsorber.

Another object is to avoid the necessity of extreme accuracy inconstructing the brake shoes and to thereby reduce the cost ofmanufacture.

In this invention I have provided a floating frictional expansiblesurface for the stationary circular wall in order to avoid un even wearand insure practically uniform gripping action.

The accompanying drawings illustrate the invention.

Figure l is a sectional View on line w1-a21, Fig. 2, of a shock absorberconstructed in accordance with this invention. Fig. 2 is a sectionalview of the shock absorber on irregular line aig-ai shown in Fig. 1 andpartly indicated in Fig. 3. Fig. 3 is a side elevation of the shockabsorber applied Specification of Letters Patent.

`as in the former application,

Patented May d, 1915.

Application filed January 24, 1912. Serial N0. 673,226.

for lise. Fig. et is an elevation of the tioating yielding band.

Two relatively rotatable elements 1, 2 are, connected to two relativelymovable parts 3, l of the vehicle through practical means as the capscrew 5 securing the part l to the chassis 3; and the arm G, pin 7connecting rod 8, pin 9 and clip 10 that connect the element 2 with thespring t.

The element 1 comprises a plate having blocks or posts 11 projectingfrom one side and providing an axial cylindrical chamber 12 and radialways therefrom having inner parallel sided portions 13 and outeroutwardly widened portions ll; the cylindrical chamber 12 being adaptedto accommodate aL floating axially movable wedge block 15 that is freeto move laterally as well as axially and is provided with recesses 1Gregistering with, and of the same width as the inner radial ways 13;there being wedges 17 adjustable in the ways 1G and 13; said wedgeshaving concave grooves 1S on their outer faces to articulate with theouter edges of iioating toggle bars 19, which are round to articulatewith notches 2O inresilient segmental brake shoes 21 that are normallyunconformed in their outer contour to the fric-y tional surface withwhich they are to engage.

Inside the circular-.wall of the ringwlike element f2. is a liningformed as a yielding Heating expansible friction-band or wearlring 23arranged encircling the segmental shoes 2l. Said Heating friction-bandis preferably al circular wrought iron band of uniform thicknessthroughout its circumference, open on one side by means of a spiral ordiagonal cleft 2l so that the band is capable of being expanded by thepressure of the shoes to frictionally engage the inner face of wall 22and produce greater or less resistance against rotation as the shoes aremadcto lightly7 or forcibly engage. the band. Said band is preferablyprovided with perforations 25 arranged in staggered relation to eachother to admit oil freelyv from the interior chamber in which the shoesand their operative parts are mounted.

'A cap :'26 is fastened by screws Q7 to the posts 1l and is providedwith a central perforation 28, through which an adjusting screw 29loosely extends to engage the lioating wedge block 15; a stiff spiraltake-up spring 30 being provided between the cap 26 and the head of theadjusting screw 29 to take up the wear if any, so that when the Wedgeblock 15 is adjusted to hold the segmental shoes`21 in determinedrelation to the ring 23 and circular wall 22, such relation will beconstantly maintained though wear may occur.

kThe circular wall 22 and the segmental shoes 21 are made very hard soas to reslst wear; and the lloating band 23 is made of relatively softermaterial so that any wear that occurs will only affect the ring. rlhesegmental shoes are preferably unconforme to the floating band so thatIportions of the shoes are externally unsupported, and the toggle barsare arranged to apply pressure to parts of the shoes opposite thenormally unsupported portions so that when the toggle action is eectiveto cause outward pressure upon the inside of the shoes, such pressurewill be edective to force the shoes into greater conformity with theband thus 1ncreasing the frictional surface between the shoe and theband: the .purpose of which is to equalize the pressure throughoutpractically all portions of the wall.

The faces 31 of the posts 11 serve as stops to prevent the toggle bars19 from passing radial position so that when relative rotation occursbetween the elements 1 and 2 the first effect is to tighten the shoes tothe extent determined by the Hoating adjusting block 15 thus producingthe desired frictional resistance to such rotation and this resistanceremains constant until reverse movement of the spring 4. The oppositefaces 32 of said posts limit the releasing movement of the toggle bars.

1n Fig. 1 the parts are shown in the released position that is caused bythe compression of the spring 4; and upon recoil of the spring, the arm6 will be drawn down ward causing the ring 2 to rotate anti-clockwise,thus frictionally dragging the floating band and the brake shoes in thesame direction and causing the brake shoes to move the toggle bars intoradial position to expand the wear-ring 23, thus to exert maximumretarding effect previously determined by the adjustment of theadjusting screw 29. 1t is seen that, owing to the expansibility of thewear-ring 23, flexure of the brake shoes 21 will gradually bring moreand more of the outer faces of the shoes against the wearring so as togradually expand vthe wear-ring into closer and closer fractionalrelation to the wall 22 and gradually increase the friction from zero tomaximum, thus avoiding too sudden clutching action and insuring perfectease of action in absorbing shocks. The shoes are at all times held infrictional relation to the floating band; and said band is at all timesin frictional relation with the circular wall 22.

1 have discovered lthat in operation the means operatable mance? oatingband travels sufliciently relative to the ring and the shoes to equalizethe wear and thus maintain a practically uniform retarding action.Preferably the shoes are of different normal radius than, and do notnormally conform to the frictional lining of the wall and there areformed between the contact points 33 of the shoes, intermediate greaseor oil chambers 34 between the shoes and the wear ring 23 when thedevice is in a releasing position.

As the resilient shoes return to normal form there occurs a tendency tosuction that causes a flow of lubricant into the space between the shoeand the friction band; and as the shoe is forced toward conformity withthe band the lubricant is forced by the shoe through the perforations 25of the band and into the space between the band and the wall 22. v

The blocks or posts 11 may be cast in skeleton form as shown, forlightness and to provide increased oil space. rlhe spiral or diagonalcleft 24 of the floating band enables the shoes to ride over the cleftwith a practically smooth and unobstructed action, but at the same timetends to effect a sufficient unbalancing of the forces acting on theband to assist in causing the band to creep around relative to thecircular wall and the shoes, and to thus prevent the shoes from makingpits or uneven places in the wall.

1. 1n a shock absorber the combination with a rotatably mounted circularwall; of a loose floating expansible band inside the wall; a shoe insidethe band and means operatable by rotation of said circular wall to forcethe shoe against the band to effect frictional action between the shoeand the band and between the band and the wall.

2. ln a shock absorber the combination with a rotatably mounted circularwall; of a loose floating open expansible band inside the wall; a shoeinside the band and means operatable by rotation of said circular wallto force the shoe against the band to eect frictional action between theshoe and the band and between the band and the wall.

3. ln a. shock absorber the combination with a rotatably mountedcircular wall; of a loose floating expansible band inside the wall; aresilient shoe inside the band; and

by rotationof said circular wall to force the shoe against the band toeffect frictionalaction between the shoe and the band and between theband and the wall.

4. The combination with a circular ring wall; of a resilient 'shoehaving inside the wall a segmental frictional surfacega ioating openexpansible band practically tting the inside of the wall and surroundingthe shoe, and havin in contact with the frictional surface o the shoe aninner circular yiso frictional surface to which the frictional surfaceof the shoe is normally uncon formed; and means operable' to deflect theshoe toward conformity with said inner frictional surface.

5.. In a shock absorber the combination,

with a circular ring wall; of a shoe; a floating open expansiblebandbetween the. shoe and the Wall 5 said shoe and band having adjacentfrictional faces that are normally unconformed to each other; and meansto cause a relative change of shape between the frictional faces of theshoe and band thereby to increase the. contacting frictional areabetween the shoe and the band.

6. In a shock absorber the combination with a. circular ring Wall; of ashoe; a floating open expansible band between the shoe and the Wall;saidshoe and band having adjacent frictional faces that are normallyunconformed to each other; and means to delcct the shoe to cause theadjacent frictional faces of the shoe and band to more nearly conform toeach other.

7. In a shock absorber the combination with a circular ring Wall; of anopen yfloat- Copies of this patent may be obtained for ve cents each,`by addressing the -pansible wear-ring between the ing expansible kbandpractically tting the inside of the wall and having an internal annularfrictional surface; a shoe having a frictional surface inside of,adjacent to, and of different normal radius than the internal frictionalsurface of the band; and means to apply force to the shoe to deflect itsfrictional surface toward conformity with the frictional surface of thefloating band.

8. A shock absorber comprismg. a circular wall, a liexible shoe having acurved face normally unconformed to the wall, an eX- shoe and the wall,and means to cause exure of the shoe to bring more and more of itscurved face against the Wear-ring to gradually expand the wear-ring intocloser and closer frictional relation to the Wall.

In testimony whereof, I my hand at Los Angeles, ary, 1912.

have hereunto set California, J anu- GEo. cUsHING MARTIN.

In presence of- JAMES R. TOWNsEND, L. BELLE RICE.

Commissioner ot Patents,

Washington, D. C.

